About us
About TimeDateLab
TimeDateLab is a set of free time and date calculators, available in English and Simplified Chinese. Every calculator shows the rules it uses, runs in your browser, and needs no account.
What you can calculate
What we care about
- Clear rules
- Every calculator shows how it counts — overnight shifts, included end dates, rounding — so you are never left guessing.
- Local calculation
- Calculations run in your browser without a calculation API. Third-party analytics and advertising process page data separately; see Privacy.
- Free, no sign-up
- Open a page and start. No account, no email address, no paywall.
- Works for everyone
- Built for keyboards, screen readers and small phone screens, in light or dark mode.
Who it's for
- Shift workers and freelancers
- Check the hours on a timesheet or an invoice, including night shifts and unpaid breaks.
- Managers and small teams
- Total a week of shifts and see how much time falls above an overtime threshold you choose.
- Planners and students
- Count the days to a deadline, an exam or an event, and how many of them are weekdays.
- Anyone checking a time
- Settle how long something really took, from a meeting to a long drive.
What TimeDateLab doesn't do
Each calculator does one job well and is upfront about its limits:
- Time zones and daylight saving
- Times are compared as they appear on the clock. The calculators do not adjust for time zones or daylight-saving changes.
- Public holidays
- Weekdays are Monday to Friday. Public and regional holidays are not subtracted.
- Pay and legal overtime
- Work Hours and Time Card calculate time, not pay, tax, or what any law counts as overtime.
Frequently asked questions
Is TimeDateLab free?
Yes. Every calculator is free to use, with no account and no premium tier. The site is supported by ads.
Are the times and dates I enter sent anywhere?
No calculation API receives them to produce results. However, shared URLs contain inputs, and third-party analytics and advertising scripts may process URLs and page activity. Do not share sensitive inputs; see the Privacy Policy.
Why doesn't it handle daylight saving time?
Most people want the time on the clock: a 9:00 to 17:00 shift is 8 hours. Mixing clock time with time-zone rules would make results change without warning, so the calculators stay with clock time and say so.
Can I rely on the results?
Each calculator follows the rules documented in the Calculation Methodology and is tested against them. For pay, legal or contractual decisions, please double-check the figures; the Terms of Service explain why.
How do I report a problem?
Email support@timedatelab.com. It helps to say which calculator you used, what you entered, and what you expected to see.
Contact us
Have a question, a suggestion or a bug to report? We read every message.